I remember working for a Sydney west holden dealer long ago testing (pre delivery) of new VB's etc around that era, one of the tests is to select reverse in the auto while moving, it's not meant to select it, one day a 253 wagon while doing about 35 mph "did".
Woohoo, does it ever lock up the rear end big time, not to mention the damage to the gearbox and drive train.
Don't ever try it even at only 10 mph.
That car was sent back to GMH broken.